/* 
 * [New BSD License (BSD 3-Clause License)]
 * Copyright (c) 2012, Max Bechtold
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     - Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     - Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     - Neither the name of the Rel2Xml Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package maxbe.rel2xml.generator.docs.constraints;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import java.util.Random;

import maxbe.rel2xml.generator.docs.DataType;

import org.apache.log4j.Logger;

/**
 * Class for generating date value
 * 
 * @author Max Bechtold
 * 
 */
public class Dates implements ValueConstructor {

	private static final String TIMEFORMAT = "yyyy-MM-dd HH:mm:ss";

	private static SimpleDateFormat sdf = new SimpleDateFormat(TIMEFORMAT);

	private Logger log = Logger.getLogger(Dates.class);
	private long minDate = -1;
	private long maxDate = -1;

	boolean now;

	private static long seed = 447291562;
	private Random rand;

	private static final List<DataType> types;

	static {
		types = new ArrayList<DataType>();
		types.add(DataType.DATETIME);
	}

	public Dates() {
		now = true;
	}

	public Dates(String minDate) {
		now = false;
		maxDate = -1;
		try {
			this.minDate = sdf.parse(minDate).getTime();
		} catch (ParseException e) {
			log.error(e);
		}
	}

	public Dates(String minDate, String maxDate) {
		now = false;
		rand = new Random(seed++);

		try {
			this.minDate = sdf.parse(minDate.replace('_', ' ')).getTime();
			this.maxDate = sdf.parse(maxDate.replace('_', ' ')).getTime();
		} catch (ParseException e) {
			log.error(e);
		}
	}

	@Override
	public boolean lengthVaries() {
		return false;
	}

	@Override
	public int getLength() {
		return -1;
	}

	@Override
	public int getSubLength() {
		return -1;
	}

	@Override
	public void announce(int number) {
		// Ignore
	}

	@Override
	public List<DataType> getSupportedDataTypes() {
		return types;
	}

	@Override
	public void mark(int number) {
		// Ignore
	}

	@Override
	public boolean needsAnnounce() {
		return false;
	}

	@Override
	public String next() {
		if (now) {
			return sdf.format(new Date());
		} else if (maxDate == -1) {
			return sdf.format(new Date(minDate));
		} else {
			long millis = Math.round(rand.nextDouble() * (maxDate - minDate))
					+ minDate;
			return sdf.format(new Date(millis));
		}
	}

	@Override
	public List<String> next(int number) {
		List<String> result;

		if (now) {
			String next = sdf.format(new Date(System.currentTimeMillis()));
			result = Collections.nCopies(number, next);
		} else if (maxDate == -1) {
			String next = sdf.format(new Date(minDate));
			result = Collections.nCopies(number, next);
		} else {
			result = new ArrayList<String>(number);
			for (int i = 0; i < number; i++) {
				long millis = Math.round(rand.nextDouble()
						* (maxDate - minDate))
						+ minDate;
				result.add(sdf.format(new Date(millis)));
			}
		}

		return result;
	}

	@Override
	public String toString() {
		return (now ? "current " : "random ")
				+ "date"
				+ (minDate > 0 ? String.format("within [%s, %s]",
						sdf.format(new Date(minDate)),
						sdf.format(new Date(maxDate))) : "");
	}

}
